Window cleaning apparatus capable of manipulation via magnetic attraction and control method thereof

ABSTRACT

An apparatus for cleaning windows comprising: a first cleaning unit, which is positioned on one side of a window, having a built-in first magnetic module comprising a magnet or a magnetic material; and a second cleaning unit, which is positioned on the opposite side of the window on which the first cleaning unit is positioned, having a built-in second magnetic module comprising a magnet or a magnetic material so as to generate magnetic attraction with the first magnetic module of the first cleaning unit, wherein the first and second cleaning units, each attached to either sides of the window, respectively, due to the magnetic attraction, clean one or both sides of the window while moving together.

TECHNICAL FIELD

The present invention relates to a magnetic attachment type window cleaning apparatus in which a pair of cleaning units each having a built-in magnet or the like, which are attached to both surfaces of a window by means of magnetic attraction, clean the outer surface or both surfaces of the window simultaneously while moving along the surface of the window.

More particularly, the present invention relates to an improved window cleaning apparatus in which cleaning units are moved on the surface of a window in a state of being brought into close conact with the surface of the window to actively adjust the magnetic attraction between the cleaning units depending on the thickness of the window so that a cleaning operation can always be performed with a constant force to respond to different thicknesses of the window. In particular, the present invention relates to an improved window cleaning apparatus which can avoid a risk of escaping and falling down of the cleaning unit from a window due to an unexpected external shock during the actual use of the window cleaning apparatus.

BACKGROUND ART

In general, if glass windows installed on wall surfaces of a building are allowed to stand for a long period of time, they are easily contaminated by being influenced by external dust, environmental pollution, rainwater, and the like, and thus become dirty. For this reason, the windows installed on the outer wall of the building are required to be frequently washed in a proper cycle in order to maintain a daylighting property and an aesthetic sense. However, in such a window washing work, the inner surface of the window where a person's hands reach can be cleaned relatively easily using rags or the like. On the other hand, since the outer surface of the window where a person's hands do not reach well is very inconvenient and difficult to clean, the dirty window is generally left to stand. In particular, in case of the veranda window of high-rise apartments, it is required that a person should wash the window while watching the outside view with him or her sticking his or her head out of the window in order to clean the outer surface of the window. Thus, conventionally, there occurs a problem in that the cleaning of the window is inconvenient and involves a considerable risk in terms of safety. In an attempt to solve the problem, there have been developed various window cleaning devices which can wash the window more conveniently and safely.

Among these window cleaning devices, the window cleaning devices which are currently used most conveniently are so-called magnet type double-sided window cleaning devices that allows a user to clean both surfaces of a glass window at the inner side of a building. Such a conventional double-sided glass window cleaning device has a slight difference in the detailed structure depending on each product, but is basically configured such that a pair of cleaning units having a built-in magnet are disposed on the indoor and outdoor side surfaces of the window so that a user moves the indoor side window cleaning unit along the surface of the window to wash the window with him or her griping it in a state in which the cleaning units are attached to each other, and thus the washing operation can be performed on the outdoor and indoor side surface of the glass window simultaneously.

The window cleaning device that is configured to simultaneously clean the indoor side surface or both surfaces of the window using the magnet has currently been developed in various forms. Such a magnet type glass window cleaning device can easily found in a plurality of documents including Korean Patent Registration No. 550279, Korean Patent Laid-Out Publication No. 10-2006-0085274, and Korean Utility Model Registration No. 0305524.

Such a conventional magnet type window cleaning device has an advantage in that a user can clean the outdoor side surface of a window even without going out but still entails problems in that since the user moves the cleaning device by applying a force to a body unit with him or her gripping a handle personally to clean the window, he or she suffers from an inconvenience in use, and in that if the user does not apply a force in parallel with the glass surface to move the cleaning device, the outdoor side cleaning unit frequently falls down from the window. In addition, the conventional magnet type window cleaning device has disadvantages in that since the cleaning device is moved along the surface of the window only once to clean the window, old dirt stuck to the window is difficult to clean clearly, and in that in the case where a window is positioned at a high position where a user does not reach, he or she suffers from an inconvenience of having to climb up to the window using a ladder or a chair to clean the window.

Accordingly, the present inventor has developed an automatic window cleaning robot that can perform a cleaning operation while moving on the surface of the window in an attempt to improve the problems associated with the conventional magnet type window cleaning device. The automatic window cleaning robot has been registered as Korean Patent Registration Nos. 10-1003486 and 10-0987121. The window cleaning robot according to the previously registered invention includes indoor and outdoor side robot units employing a drive wheel having a built-in magnet or magnetic material and uses a magnetic attraction between the drive wheels as a normal force necessary for the friction drive so that the robot units automatically perform a cleaning operation while being moved in a state of coming into close contact with the surfaces of the window. According to the previously registered invention as described above, there is provided a mechanism that can be automatically moved by the drive wheel on the surface of the window, which is perpendicular to the ground surface so that an inconvenience involved in the conventional cleaning device is resolved in which a user must move the cleaning device with him or her gripping it personally to clean the window, and thus a window cleaning operation can be performed effectively.

However, the present inventor was developing the product in order to put the previously registered invention on the market, and as a result found that if the previously registered window cleaning robot is actually commercialized, there is a need for an improvement of the window cleaning robot in terms of convenience in use and safety.

In other words, as described above, in case of the magnet type cleaning device in which the adhesion force of the cleaning device against the window is maintained by the magnetic attraction of the magnets, if a magnetic force becomes weak, the cleaning device may fall down due to escape from the surface of the window. In this case, since the product may be damaged, leading to a great personal accident, a sufficiently strong magnet must be used in view of safety. However, there is a significant difference in the thickness of a glass substrate used in the window depending on its structure (i.e., single window or double window, thickness of glass used, etc.). Thus, the conventional window cleaning device has a disadvantage in that it is impossible to properly maintain a constant magnetic force between the magnets to cope with various thicknesses of the window.

Consequently, according to the conventional window cleaning device using the magnet, in the case where the window has a small thickness, a force by which the cleaning unit comes into close contact with the window is too strong, the smooth drive of the cleaning device is difficult. In addition, there is a risk that glass will be broken due to an abrupt press and shock in the process in which the cleaning unit is attached to both surfaces of the window. On the other hand, in the case where the window has a large thickness, the magnetic force between the cleaning units and the adhesion force are weak, it is difficult for the cleaning units to be attached to the window or to be operated. In addition, there is a problem in which the cleaning unit falls down from the window due to a weak shock.

In addition, in case of the conventional window cleaning device using a magnet, the cleaning unit is attached to the window in a self-attachment manner in dependence on the magnetic attraction between the cleaning units without using a separate device for fixing the cleaning units to the window. Thus, in the case where the magnetic attraction between both cleaning units is reduced by an external factor, there is a risk that the cleaning units will lose the adhesion force and fall down from the window due to escape from the window. That is, there are considerable factors capable of inducing an instantaneous reduction in the magnetic attraction between both cleaning units due to either an unexpected external shock (e.g., wind, contact with a pedestrian, etc.) or projection of the surface of the window (e.g., in the case where a sticker is attached) during the use of the window cleaning device. In this case, there occurs a problem in that the cleaning units may fall down from the window due to escape from the window, and thus a technical solution to this problem has been emphasized as a very important issue in order to put the product on the mark.

In regard to a safety-associated problem, the conventional window cleaning device using a magnet has complemented a falling preventive safety device in various manners. As an example of the falling preventive safety device, there is disclosed Korean Utility model Registration No. 20-030552 in which an outdoor side cleaning unit includes a safety strap loop securely fixed to a window frame so that when the cleaning unit falls down from the window, it is suspended in the air without being dropped to the ground. Alternatively, the outdoor side cleaning unit includes a vacuum pump and an adsorption plate so that the adhesion force of the magnet is reinforced through a pressure sucked by the adsorption plate.

However, the conventional window cleaning device using the safety strap loop has an advantage in that it is easily applied to the window due to a relatively simply structure, but still has a problem in that since the window cleaning device encountering a simply falling accident is configured so as to be caught in the middle to prevent it from being dropped to the ground, the safety strap has a considerably long length and thus the window cleaning device collides against the wall surface of lower floors or the glass window during the falling down thereof, leading to a breakage. Fragments and glass pieces of the broken window cleaning device are dispersed in the air, resulting in a risk that induces an great injury to a pedestrian walking on the ground

In addition, the conventional window cleaning device using the vacuum pump and the adsorption plate involves problems in that since it includes a separate complicated device, the manufacturing cost and weight increase, and in that since the device is not freely moved during the suction of the adsorption plate, it is not suitable for the window cleaning device that cleans the window while moving along the surface of the window.

DISCLOSURE OF INVENTION Technical Problem

Accordingly, the present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide an improved window cleaning apparatus in which the magnetic attraction between the magnets is maintained in a proper strength by actively controlling the distance between the magnets depending on different thicknesses of the window so that the cleaning units can be moved stably, and the window is always cleaned with a constant force so that a smooth cleaning operation can be performed.

Another object of the present invention is to provide a window cleaning apparatus and a control method thereof in which in the case where there is a risk that the cleaning unit will be dropped to the ground due to an unexpected external shock applied to the window cleaning apparatus during the use of the apparatus, the strength of the magnetic force of the magnets is increased by the control of the distance between the magnets, thereby preventing a safety accident of a user, and in which a risk of escaping of the cleaning unit from the window is predicted through a combination of a force sensor and a hall sensor before the distance between the cleaning units is increased further so that a user can promptly perform a safety process, thereby ensuring a very excellent safety.

Technical Solution

To achieve the above object, in one aspect, the present invention provides a window cleaning apparatus enabling the control of a magnetic attraction in which a pair of cleaning units respectively attached to both surfaces of a window by means of the magnetic attraction therebetween clean one surface or both surfaces of the window simultaneously while moving together along the surface of the window, the apparatus comprising: a first cleaning unit disposed on one side of a window and having a built-in first magnetic module comprising a magnet or a magnetic material; and a second cleaning unit disposed on the other side of the window so as to be opposed to the first cleaning unit, and having a built-in second magnetic module comprising a magnet or a magnetic material so as to generate a magnetic attraction between the first magnetic module and the second magnetic module, wherein the first cleaning unit comprises: a magnet moving module for moving the first magnetic module either towards or away from the second magnetic module; a sensor module comprising at least one sensor, and providing information detected from the sensor; and a control module for controlling the drive of the magnetic movement module based on the information provided by the sensor module.

In addition, in the window cleaning apparatus of the present invention, preferably, the drive wheel may comprise a first drive wheel included in the first cleaning unit, and a second drive wheel included in the second cleaning unit, and wherein each of the first drive wheel and the second drive wheel has a built-in magnet or magnetic material so that the first drive wheel and the second drive wheel are brought into close contact with the surface of the window by means of the magnetic attraction therebetween. This also is one of the key technical features provided by the present invention. In this case, the first sensor unit may comprise a load cell, and the second sensor unit may comprise a hall sensor.

In addition, in another aspect, the present invention provides a method for controlling the operation of a window cleaning apparatus enabling the control of a magnetic attraction. The method comprises: (a) a primary emergency drive step of comparing a value of a force sensor or a pressure sensor, which is detected by a first sensor unit, with a preset reference value, and if the value is out of the preset reference value, allowing a control module to control a magnet moving module to move a first magnetic module in a direction of approaching from a second magnetic module; and (b) a secondary adjustment drive step of allowing the control module to control the magnet moving module to be moved to move the first magnetic module in a direction of approaching or going away from the second magnetic module so that a value of a magnetic sensor, which is detected by a second sensor unit, falls within a preset value range.

Advantageous Effects

According to the window cleaning apparatus and the control method thereof as constructed above have the following advantageous effects.

The magnetic attraction between the magnets is maintained in a proper strength by actively controlling the distance between the magnets depending on different thicknesses of the window so that the cleaning units can be moved stably, and the window is always cleaned with a constant force so that a smooth cleaning operation can be performed.

In addition, according to the present invention, in the case where there is a risk that the cleaning unit will be dropped to the ground due to an unexpected external shock applied to the window cleaning apparatus during the use of the apparatus, the strength of the magnetic force of the magnets is increased by the control of the distance between the magnets, thereby preventing a safety accident of a user. In particular, a risk of escaping of the cleaning unit from the window is predicted through a combination of the force sensor and the hall sensor before the distance between the cleaning units is increased further so that a user can promptly cope with the risk, thereby ensuring a very excellent safety.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention in conjunction with the accompanying drawings, in which:

FIG. 1 is a schematic perspective view illustrating the entire use state of a window cleaning apparatus according to a preferred embodiment of the present invention;

FIGS. 2 and 3 are views in detail illustrating a first cleaning unit of the window cleaning apparatus of the present invention shown in FIG. 1;

FIG. 4 is a view in detail illustrating a second cleaning unit of the window cleaning apparatus of the present invention shown in FIG. 1;

FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 2, wherein a main configuration portion of the present invention is shown which controls the magnetic attraction by moving a magnetic module in the window cleaning apparatus of the present invention;

FIG. 6 is a cross-sectional view illustrating another example of a main configuration portion of the present invention which controls the magnetic attraction by moving a magnetic module in the window cleaning apparatus of the present invention;

FIG. 7 is a view illustrating a magnet structure of a magnetic module and an operation of the magnetic module by the magnetic coupling when the magnetic module is coupled to a wiper in the window cleaning apparatus according to the present invention;

FIG. 8 is a view illustrating a magnet structure of a magnetic module and an operation of the magnetic module by the magnetic coupling when the magnetic module is coupled to a drive wheel in the window cleaning apparatus according to the present invention; and

FIG. 9 is a schematic block diagram illustrating the configuration of an entire system of the present invention.

Explanation on Reference Numerals of Main Elements of the Drawings

100: first cleaning unit

200: second cleaning unit

110: main body frame

112: outer housing

120: first drive wheel

125: wheel drive motor

130: first wiper

135: wiper drive motor

140: control module

150: first magnetic module

160: magnet moving module

162: movable plate

164: cam drive motor

165: cam rotary plate

166: cam post

167: screw drive motor

168: lead screw

170: sensor module

220: second drive wheel

230: second wiper

250: second magnetic module

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the configuration, operation and control method of a window cleaning apparatus according to the present invention will be described hereinafter in more detail with reference to the accompanying drawings.

FIGS. 1 to 4 are views illustrating a window cleaning apparatus according to a preferred embodiment of the present invention, wherein FIG. 1 is a schematic perspective view illustrating the entire use state of a window cleaning apparatus according to a preferred embodiment of the present invention, FIGS. 2 and 3 are views in detail illustrating a first cleaning unit of the window cleaning apparatus of the present invention shown in FIG. 1, and FIG. 4 is a view in detail illustrating a second cleaning unit of the window cleaning apparatus of the present invention shown in FIG. 1.

As shown in FIG. 1, the window cleaning apparatus according to the present invention is a cleaning apparatus that two independent cleaning units are attached to both sides of a window without any detachment and are moved together to wash the window using a magnetic force without any separate built-in support device. Referring to FIG. 1, it can be seen that the window cleaning apparatus according to the present invention consists of a set of two cleaning units such that it includes a first cleaning unit disposed on one side of a window and a second cleaning unit disposed on the other side of the window so as to be opposed to the first cleaning unit.

Referring to FIG. 1, the first cleaning unit 100 is disposed on an indoor side surface of both surfaces of a glass window, and the second cleaning unit 200 is disposed on an outdoor side surface of the glass window. In addition, the first cleaning unit 100 and the second cleaning unit 200 include magnetic modules 150 and 250 for generating a magnetic force therein, respectively, so that they are attached to both surfaces of the glass window so as to confront each other by means of the magnetic attraction between the magnetic modules in use.

Herein, the first cleaning unit 100 is a main unit that is disposed on the inner surface of the window installed on a wall of a building such as an apartment or the like. Referring to FIG. 2, the first cleaning unit 100 is configured such that it includes a wheel drive motor 125 therein so as to rotate a first drive wheel 120 so that it can be moved on the inner surface of the window by an external or internal power source. In case of most conventional magnetic attachment type cleaning apparatuses, when a user moves an indoor side cleaning unit of two cleaning units by applying a force to the cleaning unit while gripping it with his or her hands, an outdoor side cleaning unit is moved by means of the magnetic attraction between the indoor side cleaning unit and the outdoor cleaning unit. On the other hand, in case of the inventive window cleaning apparatus shown in the drawings, a drive wheel is brought into close contact with the inner surface of the window by means of the magnetic attraction of magnets to generate a frictional force necessary for movement of the cleaning unit, and thus the cleaning unit is automatically moved to perform a cleaning operation while maintaining a state of being attached to the surface of the window, thereby improving a convenience in use.

In the meantime, the configuration of the first cleaning unit 100 of a preferred embodiment of the present invention shown in FIG. 1 will be described hereinafter in more detail with reference to FIGS. 2 and 3.

The first cleaning unit 100 may basically include a main body frame 110 that forms a body as a support structure, a first wiper 130 mounted on one side of the main body frame 110 so as to scrub and wash the surface of the window 10, a first drive wheel 120 as a wheel member that is moved in a rolling manner while coming into close contact with the surface of the window 10, and a first magnetic module 150 as a magnetic force generating means. In addition, the first cleaning unit 100 may further include a wiper drive motor 135 that rotates the first wiper 130, and a wheel drive motor 125 that provides a rotation drive force to the first drive wheel 120. A control module 140 (not shown) may be provided to control various operations including the automatic movement of the window cleaning apparatus, the drive of the wiper, and the drive of the magnetic module which will be described later. (N)

The first drive wheel 120 is mounted on the inner surface of the main body frame 110 so that the first cleaning unit 100 can be brought into close contact with the surface of the window 10 in a rolling manner to cause the first cleaning unit 100 to be moved along the surface of the window 10. In the present invention, the first drive wheel 120 may have a structure in which it includes a cylindrical permanent magnet built in a central portion thereof so that it can be coupled with the second drive wheel 220 by the magnetic attraction between the first drive wheel 120 and the second drive wheel 220. In addition, the first drive wheel 120 may have a structure in which it includes a frictional cover made of a rubber material formed at a periphery thereof so that when the first drive wheel 120 is moved on the surface of the window 10 while being brought into close contact with the surface of the window 10 in a rolling manner, sliding is prevented to transmit a smooth drive force. In the meantime, it is to be, of course, noted that the frictional cover encircling the outer peripheral surface of the first drive wheel 120 is not limited to the rubber material but may be made of various materials having a proper friction coefficient to prevent sliding.

The first wiper 130 serves to clean the surface of the window while coming into close contact with the surface of the window 10 when the first cleaning unit 100 is moved on the surface of the window 10. As shown in the drawings, the first wiper 130 is mounted on the inner surface of the first main body frame 110 so as to be rotated about a rotary shaft 132 so that it can be brought into close contact with the surface of the window 10 in a sliding manner while being rotated on the surface of the window 10. In a preferred embodiment of the present invention, the first wiper 130 is formed in the shape of a disk which is rotated about the rotary shaft 132 formed perpendicular to the surface of the window. Although the number of the first wiper 130 is four, the first wiper 130 may be provided to have various shapes and numbers depending on the selection of a person of ordinary skill in the art. In addition, the direction of the rotary shaft may be modified. The first wiper 130 may further include a brush attached to the outer peripheral surface thereof so as to be brought into close contact with the surface of the window 10 so that the surface of the window 10 is cleaned effectively. Alternatively, the first wiper 130 may further include a fabric cover made of microfiber attached to the outer peripheral surface thereof.

Meanwhile, according to the present invention, the first cleaning unit 100 and the second cleaning unit 200 which will be described later include a first magnetic module 150 and a second magnetic module 250 as a means for generating a magnetic force, respectively, each of which has a built-in magnet or a magnetic material. Preferably, the first magnetic module 150 and the second magnetic module 250 include a permanent magnet to serve to generate a magnetic force therebetween so that the first cleaning unit 100 and the second cleaning unit 200 are detachably attached to both surfaces of the glass wind. Thus, the first and second cleaning units 100 and 200 respectively disposed on both surfaces of the glass window are attracted to each other and are brought into close contact with each other so that they can be moved simultaneously on the both surface of the window without any detachment.

The installation position of the first magnetic module 150 is not limited particularly, but is preferably is disposed inside first cleaning unit 100 so as to be positioned in proximity to the window so that the first magnetic module 150 can smoothly perform a magnetic coupling with the second magnetic module 250 of the second cleaning unit 200. As shown in FIGS. 1 to 3, according to the preferred embodiment of the present invention, the first magnetic module 150 is configured in the shape of a disk conforming to the shape of the first wiper 130 so that the first magnetic module 150 is fixedly coupled to the first wiper 130. The second magnetic module 250 is also coupled to the second wiper 230 correspondingly.

As such, according to the configuration in which the magnetic modules 150 and 250 are coupled to the first and second wipers 130 and 230, advantageously, the first wiper 130 and the second wiper 230 can be brought into close contact with both surfaces of the window with a proper force by means of the magnetic attraction between the magnetic modules, and thus contaminants adhered to the surfaces of the window can be removed cleanly, thereby ensuring a more efficient cleaning operation. In addition, more preferably, the magnet included in the first magnetic module 130 is configured such that such that polarities of the predetermined polar regions divided radially are changed in the circumferential direction of the rotary shaft, i.e., an N-polarity region and an S-polarity region are alternately arranged with each other as shown in FIG. 6. By virtue of this configuration, when the first wiper 130 is rotated, the second wiper 230 of the second cleaning unit 200 is operated in cooperation with the first wiper 130 so as to be rotated together with the first wiper 130. Thus, advantageously, the second cleaning unit 20 need not include a separate drive motor.

In addition, the first magnetic module 150 may be coupled to the first drive wheel 120 instead of the first wiper 130. Like this, it is advantageous that when the first magnetic module 150 is coupled to the first drive wheel 120, the drive wheels are brought into close contact with the surfaces of the window by means of the magnetic attraction between the first drive wheel 120 of the first cleaning unit 100 and the second drive wheel 220 and the second cleaning unit 200 to generate a frictional force so that the cleaning apparatus is driven more smoothly.

Further, as shown in FIG. 8, more preferably, the magnetic modules coupled to the first drive wheel 120 and the second drive wheel 220 are configured such that an N polarity and an S polarity are alternately arranged from each other along the outer peripheral surfaces of the first drive wheel 120 and the second drive wheel 220 so that the second drive wheel 220 can be rotated by receiving a rotation torque from the first drive wheel 120

In the meantime, according to the key technical features of the present invention, the first magnetic module 150 is mounted in a state of being completely fixed to a certain position of the first cleaning unit 100, but is mounted in a state of being movable and displaceable. Specifically, according to the present invention, first magnetic module 150 is configured such that it can be moved in a direction of going toward or away from the second magnetic module 250 of the second cleaning unit 200. The first cleaning unit 100 further includes a magnet moving module 160 as a means for moving the first magnetic module 150.

The magnet moving module 160 can basically include a power generating means that generates a drive force such as motor and a mechanical element that converts a rotational motion into a rectilinear motion by using a rotational force of the motor. An example of the specific embodiment thereof is shown as a preferred embodiment in FIGS. 4 and 5. In addition, according to the present invention, the first cleaning unit 100 further includes a control module as a device for controlling the drive of the magnet moving module 160, and a sensor module including at least one sensor unit as a means for providing information necessary for the control of the control module. The control of the magnet moving module by the sensor module and the control module, and the acting effects according to the control thereof will be described hereinafter in more detail.

Next, the second cleaning unit 200 is a cleaning unit for cleaning the opposite surface of the window by constituting a pair with the first cleaning unit 100 while being moving on the opposite surface of the window. The second cleaning unit 200 is disposed on the other surface of the window, which is opposed to one surface of the window on which the first cleaning unit 100 is disposed so that the second cleaning unit 200 performs a cleaning operation while being moved together with the first cleaning unit 100 by means of the magnetic attraction.

Referring to FIG. 4, the second cleaning unit 200 is configured in the substantially same manner as the first cleaning unit 100. The second cleaning unit 200 includes a second main body frame 210, a plurality of second drive wheels 220, a plurality of second wipers 230, and a second magnetic module 250 for generating a magnetic force. In the second cleaning unit 200, the second main body frame 210 forms a body of the second cleaning unit 200, and the second drive wheel 220, the second wiper 230 and the like are fixedly coupled to the second main body frame 210. The second cleaning unit 200 does not include the wheel drive motor unlike the first cleaning unit 100. The second cleaning unit 200 is mounted in a state of being axially fixed to the second main body frame 210 so that when it is moved together with the second cleaning unit 200 while being magnetically attracted by the second cleaning unit 200.

The second magnetic module 250 is preferably configured such that it is coupled to the second wiper 230 in the same manner as the first magnetic module 150. But, besides this configuration, the second magnetic module 250 may be configured such that it is coupled to the second drive wheel 220 to correspond to the installation position of the first magnetic module 150 or is mounted at other positions of the second cleaning unit 200.

In addition to the basic configuration as described above, various additional configurations may be included in the first cleaning unit 100 and the second cleaning unit 200. For example, the first cleaning unit 100 and/or the second cleaning unit 200 may further include a washing solution tank (not shown) so as to clean the window more effectively. The washing solution tank is connected to a pump 185 (not shown in FIG. 3) through a hose, and sprays a proper amount of washing solution onto the surface of the window 10. In this case, preferably, the washing solution tank sprays the washing solution around the wipers 130 and 230 so that the first wiper 130 and the second wiper 230 can clean the window effectively. In a more preferred embodiment of the present invention, elements constituting the rotary shafts 132 and 232 of the first wiper 130 and the second wiper 230 are formed as hollow tubular pipes, and the pump is configured such that the washing solution is sprayed onto the window 10 through the rotary shaft 132 of the first wiper 130 so that the cleaning operation can be performed more effectively.

Moreover, in the embodiment as shown in FIGS. 2 and 4, each of the first and second main body frames 110 and 210 may further include at least one shock absorbing bumper 186 or 286 on the outer peripheral surface thereof. Each of the bumpers 186 and 286 serves to absorb a shock when the main body frames 110 and 210 collide against a window frame (not shown) provided at the edge of the window 10, thereby preventing the window frame or the cleaning unit from being damaged. Meanwhile, in the more preferred embodiment of the present invention, the bumpers 186 and 286 may include a contact sensor (not shown) for detecting the contact with an external object such as the window frame. For example, the contact sensor is implemented as a pressure sensor to detect a pressure generated upon the contact between the bumpers and the external object, but is not limited thereto. Also, it is to be, of course, noted that the contact sensor may be implemented as various known sensors such as photo sensors, which detect whether or not the bumper contacts with or approaches an object. As such, a signal generated from the contact sensor is transmitted to the control module 140 so as to be used for the control of the wheel drive motor 125.

According to the window cleaning apparatus of the present invention as constructed above, two cleaning units respectively attached to the inner and outer surfaces of a window by means of the magnetic attraction between the magnetic modules clean the window simultaneously while moving together along the surface of the window so that the cleaning operation can easily performed on the outer surface of the window. In addition, according to the key technical features of the present invention, the window cleaning apparatus' is configured to actively control the magnetic attraction between the magnetic modules so that with the cleaning operation can be performed with a constant force while maintaining a uniform adhesion force depending on different thicknesses of the window. Particularly, since a reduction in the magnetic attraction due to application of an expected external force and a risk of falling of the apparatus according to the reduction in the magnetic attraction are prevented during the drive of the window cleaning apparatus, a very excellent effect is expected in terms of safety.

Hereinafter, the technical configuration and acting effects of the present invention as a window cleaning robot enabling the control of the magnetic attraction will be described in more detail with reference to the accompanying drawings.

FIG. 5 is a cross-sectional view taken along the line A-A of FIG. 2. In FIG. 5, there is shown a preferred embodiment of a main configuration portion of the present invention which controls the magnetic attraction by moving the magnetic module in the window cleaning apparatus of the present invention. The magnet moving module 160 includes a cam drive motor 164 and a cam drive unit that converts a rotational motion of the cam drive motor 164 into a reciprocating linear motion and transmits the converted reciprocating linear motion to the first magnetic module 150 to move the first magnetic module 150.

According to the embodiment as shown in FIG. 5, the first magnetic module 150 is configured to include a permanent magnet in which an N pole and an S pole are arranged alternately in the circumferential direction (see FIG. 7). The first magnetic module 150 is configured so as to be integrally coupled to the first wiper 130. As shown in the drawings, the first wiper 130 to which the first magnetic module 150 is coupled is configured so as to be rotated about the rotary shaft 132 disposed perpendicular to the surface of the window. The rotary shaft 132 of the first wiper 130 is rotatably fixed to a movable plate 162 with it supported by the movable plate 162. The movable plate 162 is not coupled to a first main body plate and an outer housing 112 in a fixed manner, but is mounted so as to be movable in forward and backward directions. The first wiper 130, the first magnetic module 150, and the wiper drive motor 135 are integrally fixed to the movable plate 162.

The wiper drive motor 135 fixedly coupled to one side of the movable plate 162 is a motor which generates a drive force for rotating the first wiper 130. The wiper drive motor 135 and the rotary shaft 132 of the first wiper 130 are connected to each other through a gear 136 to allow the number of rotations thereof to be properly adjusted so that the first wiper 130 can be rotated.

The first wiper 130, the first magnetic module 150, the wiper drive motor 135, and the gear 136, which are coupled to the movable plate 162, forms a single assembly so as to be moved together. According to the embodiment shown in FIG. 4, the magnet moving module 160 includes the cam drive motor 164 configured to move the movable plate 162 and the first magnetic module 150 or the like coupled to the movable plate 162. The magnet moving module 160 is also provided with a cam drive mechanism for converting a rotational motion of the cam drive motor 164 into a reciprocating linear motion to move the first magnetic module 150.

According to the embodiment shown in FIG. 5, the cam drive mechanism may be configured to include a cam rotary plate 165 connected to the cam drive motor 164 so as to be rotated in response to the operation of the cam drive motor 164. It is illustrated in FIG. 5 that the cam rotary plate 165 has the shape of a slope inclined plane in which the height of a portion rising out of the bottom surface thereof varies in the circumferential direction of the central axis of the top surface thereof. Besides this configuration, a cam post 166 is formed protrudingly on the inner surface of the movable plate 162 to which the first magnetic module 150 is coupled so that a front end thereof abuts against the top surface of the cam rotary plate 165.

Thus, when the cam drive motor 164 is rotated by a predetermined angle, the cam rotary plate 165 connected to the cam drive motor 164 is rotated together with the cam drive motor 164 to cause the protruding height of the slope inclined plane of the cam rotary plate 165 abutting against the cam post 166 to vary so that the cam post 166 can be moved pushingly outwardly or can be moved inwardly by the action of a spring connected to the movable plate 162.

The forward and backward movements of the cam post 166 enable the movable plate 162 connected to the cam post 166 and the first magnetic module 150 to be moved. According to the present invention, the distance between the first magnetic module 150 and the second magnetic module 250 is adjusted by the interaction between the cam drive motor 164 and the cam drive mechanism so that the strength of the magnetic attraction between the first cleaning unit 100 and the second cleaning unit 200 can be controlled. In other words, when the first magnetic module 150 is moved in a direction of approaching the second magnetic module 250 by the operation of the magnet moving module 160, the strength of the magnetic attraction between the first magnetic module 150 and the second magnetic module 250 is adjusted to be high. On the contrary, when the first magnetic module 150 is moved in a direction of going away from the second magnetic module 250, the strength of the magnetic attraction is adjusted to be low. Thus, the adhesion force of the window cleaning apparatus against the window can be freely adjusted.

Therefore, according to the present invention, when the window cleaning apparatus having the built-in magnetic modules is moved in a stated of being brought into close contact with the surface of the window, the distance between the magnetic modules varies actively depending on the thickenss of the window so that the window can always be cleaned with a constant force irrespective of the thickness of the glass window. In addition, in the case in which there occurs a risk that the cleaning unit will escape from the apparatus or fall down from the window due to an unexpected external force during the use of the inventive window cleaning apparatus, the magnetic modules are caused to approach each other to increase the strength of the magnetic force, thereby greatly improving stability of the product.

In the present invention, the control of the operation of the magnet moving module 160 can be performed by a separate control module. In a preferred embodiment of the present invention, the control module may be implemented in the form of a microcomputer having a program installed therein. In addition, referring to FIG. 9 illustrating a schematic block diagram illustrating the configuration of an entire system of the present invention, the first cleaning unit 100 of the present invention further includes a sensor module 170 having a sensor capable of detecting information from the outside to provide information necessary for the control of the control module 140.

In the present invention, the sensor module 170 may be configured to include at least one sensor. The sensor module 170 may be basically implemented as a magnetic sensor such as a hall sensor in order to measure the strength of the magnetic attraction between the first magnetic module 150 and the second magnetic module 250. Thus, the sensor module 170 measures the strength of the magnetic attraction between the first magnetic module 150 and the second magnetic module 250 through the hall sensor to apply the measured information to the control module 140. The control module 140 outputs a control signal for application to the magnet moving module 160 based on the information applied thereto from the sensor module 170 to control the operation of the magnet moving module 160 for moving the first magnetic module 150 so that the distance between the first magnetic module 150 and the second magnetic module 250 can be adjusted to maintain a proper magnetic attraction between first magnetic module 150 and the second magnetic module 250.

Meanwhile, in the present invention, more preferably, the sensor module 170 is implemented as two sensor units including a first sensor unit 171 including a force sensor or a pressure sensor for detecting the strength of an externally acting force, a second sensor unit 172 including a magnetic sensor for detecting the strength of the magnetic attraction from the second magnetic module 250 of the second cleaning unit. In the present invention, the most basically, the sensor module 170 may be implemented as only the magnetic sensor capable of measuring the strength of the magnetic attraction between the first magnetic module and the second magnetic module. In this case, there is advantageous in that a proper adhesion force is maintained depending on various thicknesses of the window to enable the efficient cleaning. However, there is still involved a problem in that no sufficient countermeasure can be taken against a risk of falling down of the cleaning unit due to an external shock.

In other words, the magnetic sensor such as the hall sensor serves to detect the strength of a magnetic force acting on the sensor. In the case where an abrupt external force acts on the cleaning unit, the magnetic sensor does not detect a risk of falling down of the cleaning unit until the distance between the magnetic modules is increased to some extent and the strength of a magnetic force detected by the magnetic sensor is decreased. However, as described above, after the distance between the magnetic modules is increased, it is actually impossible to recover the strength of a magnetic force through the control of the magnet moving module, and thus the above-mentioned configuration has a shortcoming in that it is difficult to meet the demand for safety of the product using only the magnetic sensor.

According to the preferred embodiment of the present invention, the sensor module 170 further includes a force sensor in addition to the magnetic sensor so that it is possible to effectively cope with a problem associated with safety. In other words, the force sensor serves to detect the strength of a force acting on the cleaning unit and convert the detected force strength into an electric signal. According to the preferred embodiment of the present invention in which the sensor module 170 includes the force sensor, in the case where a strong external force acts on the cleaning unit, for example, in the case where a user touches the cleaning unit while walking, there occurs a change in the strength of a force acting on the force sensor. Thus, if there is a change in the detected value of the force sensor and thus the detected value is out of a reference value, the control module controls the magnet moving module 160 to move the first magnetic module 150 in a direction of approaching the second magnetic module 250 in a primary emergency drive step so that the strength of the magnetic attraction is increased, thereby preventing a risk of falling down of the cleaning unit.

Thus, according to the preferred embodiment of the present invention as mentioned above, before the cleaning unit begins to escape from the window, the control module predicts a risk of escape from the window to allow the magnetic modules to approach each other so that a risk of falling down of the cleaning unit due to an external shock can be avoided, thereby significantly improving safety of the product.

After the primary emergency drive step is performed, if an external force factor disappears, the control module 140 controls the magnet moving module 160 to adjust the distance between the magnetic modules through feedback movement to adjust the strength of the magnetic attraction to a proper range in a secondary adjustment drive step so that a value of the magnetic sensor, which is detected by the second sensor unit 172 falls within a preset value range.

Meanwhile, in the present invention, preferably, a strain gauge type load cell can be used as the force sensor. Besides, a piezoelectric force sensor or an inductance type force sensor may be used as the force sensor. In addition, the force sensor may be replaced with a pressure sensor capable of detecting a pressure that allows the cleaning unit to be pressed against the surface of the window.

The installation position the first sensor unit 171 including the force sensor or the pressure sensor as mentioned above can be modified in various manners depending on the design of a person of ordinary skill in the art. In particular, in the case where the force sensor is mounted between a housing 112 defining an outer casing and an inner component to which the first magnetic module 150 is connected, a user can predict the effect of an externally applied force on the first magnetic module 150 as a magnetic force generating means to cope with a risk of falling down of the cleaning unit, and the like. The force sensor 171 can be installed between the housing 112 of the first cleaning unit and the cam drive motor 164 as shown in FIG. 5. Although not shown, the force sensor 171 can be installed at various positions, such as being installed between a structure such as the movable plate 161 including the first magnetic module and the housing 112.

Further, the first sensor unit may be installed in such a manner as to detect a force or a pressure allowing the cleaning unit to be pressed against the surface of the window so that a risk of falling down of the cleaning unit can be detected by a reduction in the pressure immediately before the cleaning unit escape from the apparatus. In the case where the first sensor unit is configured in the above manner, it can be installed at a portion against which the cleaning unit and the window surface abut, for example, at the first wiper or the first drive wheel. The first sensor unit may be installed at the rotary shaft of the first drive wheel so that a risk of falling down of the cleaning unit can be detected previously through a reduction of the frictional force of the first drive wheel.

In the meantime, in the embodiment as described above, it has been illustrated that the first magnetic module 150 is movably installed. Alternatively, the first and second magnetic modules 150 and 250 may be configured such that the first magnetic module 150 is fixedly mounted and the second magnetic module 250 is movably mounted, or such that the first magnetic module 150 and the second magnetic module 250 are movable simultaneously.

FIG. 6 is a cross-sectional view illustrating another example of a main configuration portion of the present invention which controls the magnetic attraction by moving the magnetic module in the window cleaning apparatus of the present invention. In FIG. 6, a configuration is shown in which the first magnetic module is moved using a motor and a lead screw.

As shown FIG. 6, the magnet moving module 160 may be implemented to include a screw drive motor 167 and the lead screw 168 connected to the screw drive motor 167. The basic operation and action of the magnet moving module 160 is performed in the substantially same as the cam drive manner. In addition, the magnet moving module 160 can be implemented as a linear motor or other means.

INDUSTRIAL APPLICABILITY

The technology related to the window cleaning apparatus and the control method thereof according to the present invention can be applied to a window cleaning robot that has built-in magnetic modules so as to clean the window while moving with a magnetic force in a state of being attached to the surface of the window by means of the magnetic attraction between the magnetic modules.

While the present invention has been described in connection with the exemplary embodiments illustrated in the drawings, they are merely illustrative embodiments, and the invention is not limited to these embodiments. It is to be understood that various equivalent modifications and variations of the embodiments can be made by a person having an ordinary skill in the art without departing from the spirit and scope of the present invention. Therefore, the true technical scope of the present invention should be defined by the technical spirit of the appended claims. 

1. A window cleaning apparatus enabling the control of a magnetic attraction in which a pair of cleaning units respectively attached to both surfaces of a window by means of the magnetic attraction therebetween clean one surface or both surfaces of the window simultaneously while moving together along the surface of the window, the apparatus comprising: a first cleaning unit disposed on one side of a window and having a built-in first magnetic module comprising a magnet or a magnetic material; and a second cleaning unit disposed on the other side of the window so as to be opposed to the first cleaning unit, and having a built-in second magnetic module comprising a magnet or a magnetic material so as to generate a magnetic attraction between the first magnetic module and the second magnetic module, wherein the first cleaning unit comprises: a magnet moving module for moving the first magnetic module either towards or away from the second magnetic module; a sensor module comprising at least one sensor, and providing information detected from the sensor; and a control module for controlling the drive of the magnetic movement module based on the information provided by the sensor module.
 2. The window cleaning apparatus according to claim 1, wherein either the first cleaning unit or the second cleaning unit comprises a drive wheel configured to move either first cleaning unit or the second cleaning unit while being contactingly rotated on the surface of the window, and a wheel drive motor configured to provide a power for rotating the drive wheel to the drive wheel.
 3. The window cleaning apparatus according to claim 1, wherein the first cleaning unit and/or the second cleaning unit comprise/comprises a wiper configured to clean the surface of the window.
 4. The window cleaning apparatus according to claim 3, wherein the wiper is mounted so as to be rotatable about a shaft that is disposed perpendicular to or in parallel with the surface of the window.
 5. The window cleaning apparatus according to claim 1, wherein the first cleaning unit and the second cleaning unit comprise a first wiper and a second wiper that are configured to clean both surfaces of the window, respectively, and wherein the first wiper and the second wiper are mounted so as to be rotatable about a shaft that is disposed perpendicular to the surface of the window.
 6. The window cleaning apparatus according to claim 5, wherein the first magnetic module is fixedly mounted to the first wiper, and the second magnetic module is fixedly mounted to the second wiper.
 7. The window cleaning apparatus according to claim 6, wherein a wiper drive motor is provided at one side of the first wiper or the second wiper so as to drive the first wiper or the second wiper, and the first wiper and the second wiper are configured so as to be rotated in cooperation with each other by means of the magnetic coupling between the first magnetic module and the second magnetic module without providing a wiper drive means at the other side of the first wiper or the second wiper.
 8. The window cleaning apparatus according to claim 7, wherein each of the first magnetic module and the second magnetic module is composed of permanent magnets in which an N-polarity region and an S-polarity region are alternately arranged with each other in the circumferential direction of the rotary shaft of the first wiper and the second wiper.
 9. The window cleaning apparatus according to claim 2, wherein the drive wheel comprises a first drive wheel included in the first cleaning unit, and a second drive wheel included in the second cleaning unit, and wherein each of the first drive wheel and the second drive wheel has a built-in magnet or magnetic material so that the first drive wheel and the second drive wheel are brought into close contact with the surface of the window by means of the magnetic attraction therebetween.
 10. The window cleaning apparatus according to claim 9, wherein each of the first drive wheel and the second drive wheel comprises a permanent magnet in which an N pole and an S pole are alternately arranged with each other in the circumferential direction of the magnet.
 11. The window cleaning apparatus according to claim 1, wherein the sensor module comprises: a first sensor unit including a force sensor or a pressure sensor so as to detect the strength of an externally acting force; and a second sensor unit including a magnetic sensor so as to detect the strength of the magnetic attraction between the first magnetic module and the second magnetic module
 12. The window cleaning apparatus according to claim 11, wherein the first sensor unit comprises a load cell.
 13. The window cleaning apparatus according to claim 11, wherein the first sensor unit is mounted so as to detect a change in a force acting between a housing of the first cleaning unit and a structure including the first magnetic module.
 14. The window cleaning apparatus according to claim 11, wherein the first sensor unit is mounted so as to detect a change in a force by which the first cleaning unit is pressed against the surface of the window.
 15. The window cleaning apparatus according to claim 11, wherein the first sensor unit is mounted to the drive wheel or the rotary shaft of the drive wheel.
 16. The window cleaning apparatus according to claim 11, wherein the second sensor unit comprises a hall sensor.
 17. The window cleaning apparatus according to claim 1, wherein the magnet moving module comprises a cam drive motor configured to be controlled in drive by the control module, and a cam drive unit configured to convert a rotational motion of the cam drive motor into a reciprocating linear motion and transmit the converted reciprocating linear motion to the first magnetic module.
 18. The window cleaning apparatus according to claim 17, wherein the cam drive unit comprises a cam rotary plate configured to be rotated by receiving the rotational force from the cam drive motor, wherein the cam rotary plate has the shape of a slope inclined plane in which the height of a portion rising out of the bottom surface thereof varies in the circumferential direction of the central axis of the top surface thereof, and wherein the first magnetic module comprises a cam post 166 configured to be brought into close contact with the top surface of the cam rotary plate.
 19. The window cleaning apparatus according to claim 1, wherein the magnet moving module comprises a screw drive motor configured so as to be controlled in drive by the control module, and a lead screw configured to so as to be moved axially while being rotated by receiving the rotational force from the screw drive motor, and wherein the first magnetic module is configured to be connected to the lead screw directly or through another element so that the first magnetic module and the lead screw are moved together.
 20. The window cleaning apparatus according to claim 1, wherein the magnet moving module comprises a linear motor.
 21. A method for controlling the operation of a window cleaning apparatus enabling the control of a magnetic attraction in which a pair of cleaning units respectively attached to both surfaces of a window by means of the magnetic attraction therebetween clean one surface or both surfaces of the window simultaneously while moving together along the surface of the window, wherein the window cleaning apparatus comprises a first cleaning unit and a second cleaning unit, the first cleaning unit or a second cleaning unit comprising a drive wheel configured to move either first cleaning unit or the second cleaning unit while being contactingly rotated on the surface of the window, and a wheel drive motor configured to provide a power for rotating the drive wheel to the drive wheel, the method comprising: (a) a primary emergency drive step of comparing a value of a force sensor or a pressure sensor, which is detected by a first sensor unit, with a preset reference value, and if the value is out of the preset reference value, allowing a control module to control a magnet moving module to move a first magnetic module in a direction of approaching from a second magnetic module; and (b) a secondary adjustment drive step of allowing the control module to control the magnet moving module to be moved to move the first magnetic module in a direction of approaching or going away from the second magnetic module so that a value of a magnetic sensor, which is detected by a second sensor unit, falls within a preset value range. 